[Emacs-diffs] /srv/bzr/emacs/trunk r107405: Fix bug #10674 with infinite re-spawning of cmdproxy.exe.

[Eli Zaretskii]

------------------------------------------------------------
revno: 107405
fixes bug(s): http://debbugs.gnu.org/10674
committer: Eli Zaretskii <address@hidden>
branch nick: trunk
timestamp: Fri 2012-02-24 12:13:20 +0200
message:
  Fix bug #10674 with infinite re-spawning of cmdproxy.exe.
  
   nt/cmdproxy.c (main): Bypass conversion of the file name in argv[0]
   and our own module name to short 8+3 aliases, if the original file
   names compare equal.  If GetShortPathName fails, compare the base
   names of the two file names, and only re-spawn the command line if
   the base-name comparison also fails.
modified:
  nt/ChangeLog
  nt/cmdproxy.c

=== modified file 'nt/ChangeLog'
--- a/nt/ChangeLog      2012-02-23 07:52:08 +0000
+++ b/nt/ChangeLog      2012-02-24 10:13:20 +0000
@@ -1,3 +1,14 @@
+2012-02-24  Eli Zaretskii  <address@hidden>
+
+       Prevent endless re-spawning of cmdproxy.exe when some of its
+       parent directories have access limitations.
+
+       * cmdproxy.c (main): Bypass conversion of the file name in argv[0]
+       and our own module name to short 8+3 aliases, if the original file
+       names compare equal.  If GetShortPathName fails, compare the base
+       names of the two file names, and only re-spawn the command line if
+       the base-name comparison also fails.  (Bug#10674)
+
 2012-02-23  Dani Moncayo  <address@hidden>  (tiny change)
 
        * makefile.w32-in (maybe-copy-distfiles-SH): Fix typo.

=== modified file 'nt/cmdproxy.c'
--- a/nt/cmdproxy.c     2012-01-19 07:21:25 +0000
+++ b/nt/cmdproxy.c     2012-02-24 10:13:20 +0000
@@ -512,7 +512,7 @@
   char modname[MAX_PATH];
   char path[MAX_PATH];
   char dir[MAX_PATH];
-
+  int status;
 
   interactive = TRUE;
 
@@ -551,20 +551,73 @@
 
   /* Although Emacs always sets argv[0] to an absolute pathname, we
      might get run in other ways as well, so convert argv[0] to an
-     absolute name before comparing to the module name.  Don't get
-     caught out by mixed short and long names.  */
-  GetShortPathName (modname, modname, sizeof (modname));
+     absolute name before comparing to the module name.  */
   path[0] = '\0';
-  if (!SearchPath (NULL, argv[0], ".exe", sizeof (path), path, &progname)
-      || !GetShortPathName (path, path, sizeof (path))
-      || stricmp (modname, path) != 0)
+  /* The call to SearchPath will find argv[0] in the current
+     directory, append ".exe" to it if needed, and also canonicalize
+     it, to resolve references to ".", "..", etc.  */
+  status = SearchPath (NULL, argv[0], ".exe", sizeof (path), path,
+                                 &progname);
+  if (!(status > 0 && stricmp (modname, path) == 0))
     {
-      /* We are being used as a helper to run a DOS app; just pass
-        command line to DOS app without change.  */
-      /* TODO: fill in progname.  */
-      if (spawn (NULL, GetCommandLine (), dir, &rc))
-       return rc;
-      fail ("Could not run %s\n", GetCommandLine ());
+      if (status <= 0)
+       {
+         char *s;
+
+         /* Make sure we have argv[0] in path[], as the failed
+            SearchPath might not have copied it there.  */
+         strcpy (path, argv[0]);
+         /* argv[0] could include forward slashes; convert them all
+            to backslashes, for strrchr calls below to DTRT.  */
+         for (s = path; *s; s++)
+           if (*s == '/')
+             *s = '\\';
+       }
+      /* Perhaps MODNAME and PATH use mixed short and long file names.  */
+      if (!(GetShortPathName (modname, modname, sizeof (modname))
+           && GetShortPathName (path, path, sizeof (path))
+           && stricmp (modname, path) == 0))
+       {
+         /* Sometimes GetShortPathName fails because one or more
+            directories leading to argv[0] have issues with access
+            rights.  In that case, at least we can compare the
+            basenames.  Note: this disregards the improbable case of
+            invoking a program of the same name from another
+            directory, since the chances of that other executable to
+            be both our namesake and a 16-bit DOS application are nil.  */
+         char *p = strrchr (path, '\\');
+         char *q = strrchr (modname, '\\');
+         char *pdot, *qdot;
+
+         if (!p)
+           p = strchr (path, ':');
+         if (!p)
+           p = path;
+         else
+           p++;
+         if (!q)
+           q = strchr (modname, ':');
+         if (!q)
+           q = modname;
+         else
+           q++;
+
+         pdot = strrchr (p, '.');
+         if (!pdot || stricmp (pdot, ".exe") != 0)
+           pdot = p + strlen (p);
+         qdot = strrchr (q, '.');
+         if (!qdot || stricmp (qdot, ".exe") != 0)
+           qdot = q + strlen (q);
+         if (pdot - p != qdot - q || strnicmp (p, q, pdot - p) != 0)
+           {
+             /* We are being used as a helper to run a DOS app; just
+                pass command line to DOS app without change.  */
+             /* TODO: fill in progname.  */
+             if (spawn (NULL, GetCommandLine (), dir, &rc))
+               return rc;
+             fail ("Could not run %s\n", GetCommandLine ());
+           }
+       }
     }
 
   /* Process command line.  If running interactively (-c or /c not